Baggage maintenance engineers voted for three days of industrial action between April 8-10. All airlines operating out of Heathrow would be affected by the strike action, including British Airways, Air France and KLM.
If the strike goes ahead, it might not be the only issue travellers will face at airports:

• Manchester airport customers have dealt with huge queues this month as the airport deals with staff shortages. Shortages with security staff have caused issues and the airport said that staff sickness had exacerbated the problem.
• Passengers at Dublin Airport have also faced chaos with lengthy queues at check in and security.
• Tourists travelling to Spain and Portugal could also face delays as a new French air system causes flights to be diverted through German airspace.